New measurements show high air pollution in Copenhagen metro

Every year, air air pollution is chargeable for the untimely demise of 4,200 Danes and is linked by WHO to diabetes, most cancers and coronary heart illness. In Copenhagen, air air pollution is measured by a collection of measuring stations put in on the roofs of assorted elements of town.

Nevertheless, the underground air, which is breathed by 80 million individuals who use the subway yearly, has been a blind spot in measuring the air high quality of town. Now, researchers from the Division of Chemistry on the College of Copenhagen, in collaboration with Aarhus College, have for the primary time measured air air pollution underground within the Copenhagen metro system.

Measurements present that the air is polluted with dangerous ultra-small particles which are 10 to twenty occasions increased than measurements taken proper subsequent to City Corridor Sq. on HC Andersens Boulevard, the place human site visitors is heavy. It’s an space that has to date been thought-about probably the most polluted place within the capital.

“Our measurements present that the subway might be the place you expertise probably the most intense air air pollution in Copenhagen’s public area. In case you use the subway lots or work there, it could have the most important affect in your well being and will be the most important. Professor Matthew S. Johnson, from the Division of Chemistry, who led the research.” A single substance that contributes to your annual publicity. “Precautions needs to be taken to barely scale back the focus of particles,” he says.

Air air pollution within the subway is especially brought on by the iron brakes, wheels and rails of the trains. The friction of operating and slowing trains releases iron particles into the air, which make up 88 % of the particles the researchers had been in a position to establish of their evaluation.

The iron particles are so small that they will simply penetrate the lung tissue and enter the blood instantly. Subsequently, in response to WHO, they’re on the identical stage because the others. small particlesit’s dangerous to human well being.

Particles within the filter had been collected in 19 hours over three days at Nørrebros Runddel Metro station. {Photograph} by Hugo S. Russell.

Metropolis ring and Discussion board the worst

The researchers took measurements from trains on all traces and 14 subway stations. Among the many trains on the M3, Cityringen is the worst, with the particle focus on common 20 occasions increased than on HC Andersens Boulevard close to Rådhuspladsen and twice as excessive as trains on the M1 and M2 metro traces.

It is because the Metropolis ring consists of 17 underground stations and subsequently receives little or no air flow contained in the tunnel for some sections in comparison with the M1 and M2 which lie above floor.

“That is referred to as the ‘piston impact’, the place trains push the polluted air out of the tunnel as they rise above the bottom. The M1 and M2 make the most of this impact, but the air turns into an increasing number of polluted as you progress away from the bottom. Nevertheless, because the Metropolis Ring solely works underground, it achieves the pure trade of air there. You possibly can’t, only a smaller quantity of air is pushed via the vents and is subsequently far more polluted,” explains Ph. .D. Hugo S. Russell, who was chargeable for the gathering and evaluation of the samples with Niklas Kappelt of Aarhus College.

Discussion board Station takes the award because the dirtiest stations in all the metro community. For instance, Nørreport has a a lot increased particle focus in comparison with Kongens Nytorv, Christianshavn and Amagerbro.

Info in regards to the measurements:

• Scientific article revealed within the journal Setting WorldwideThe researchers conclude in 2019 that “regardless of its current building, the system is surprisingly soiled.”
• The researchers measured a median of 20 occasions the particle density within the air contained in the trains within the Cityringen M3, close to HC Andersens Boulevard, which is alleged to be one among Copenhagen’s most polluted locations.
• Nørrebros Runddel and Discussion board stations are the dirtiest in all the metro community.
• The particles are composed primarily of 88% iron, which originates from practice tracks, wheels and brakes.
• Measurements had been made in March and April 2021 for 16 days and had been carried out in working situation on trains and at stations.
• A Measurement tool Small optical particle sensors and gravimetric samplers had been used alongside the instrument referred to as the TSI DustTrak DRX Aerosol Monitor 8533.
• The composition of the gravimetric samples was analyzed by particle-induced X-ray emission (PIXE) evaluation.
• At underground stations on the M1 and M2 traces, a median stage of 109 micrograms per cubic meter was measured, 10 occasions the road stage recorded in central Copenhagen on the time of measurement (11 µg m-3 ).
• For the M3 line, the common concentrations on the trains had been 219 micrograms of particles per cubic metre; that is 20 occasions increased than road stage in central Copenhagen and better than on the platforms (168 micrograms per cubic metre), which isn’t typical by comparability. to different subway techniques.
• The EU has a objective of preserving the focus of ultrafine particles within the exterior air under a median of 25 micrograms per cubic meter for one yr.
• The World Well being Group (WHO) recommends that the common publicity over a yr be a most of 5 micrograms per cubic metre, since greater than that is estimated to be probably dangerous to well being.

Air flow can scale back air pollution

In keeping with researchers, increased issues air pollution It’s not a brand new phenomenon in metro techniques. Comparable issues have been recognized in London, Paris, Stockholm, Barcelona, ​​Seoul and Toronto, the place the answer was primarily to ventilate the air. The researchers speculate that this might additionally considerably scale back the focus of particles within the Copenhagen metro.

“In Barcelona, ​​they merely opened the vents that had been already put in however designed for temperature management and decreasing the particle focus. The Copenhagen metro additionally has an analogous sort of vents designed for fires, however they don’t seem to be in use in the present day. You may contemplate opening them,” says Professor Matthew. S. Johnson provides:

“In any other case you may have to interchange the wheels, rails and brakes with different supplies. It is a very costly job, however it’s nonetheless one thing they selected to do on the Toronto and Montreal subways,” says Matthew S. Johnson.

One other doable perpetrator for air pollution inside trains is the glass doorways that separate the platform from the practice. They assist isolate particles in tunnels and scale back air flow there. It’s a downside noticed in South Korea as nicely.

“Analysis on the Seoul subway system has proven that gates between the platform and the practice monitor enhance air high quality at stations, however make the air inside trains worse. In fact there’s a security concern, however it’s price contemplating,” says Hugo Russel.